title: Influence of agricultural wastes and a finished compost on the decomposition of slaughterhouse waste composts.
abstract: The objective of this study was to evaluate the efficacy of combining agricultural wastes or a finished compost (wheat straw, horse manure and bedding, sheep manure, and a wheat straw-SHW finished compost) as compost feedstocks with cattle slaughterhouse wastes (SHW) on a field-scale. The composts were managed in covered bins over 200 days and physico-chemical parameters related to organic matter bio-degradation were measured over time. Thermophilic temperatures were maintained above 55 °C for 12-46 days to meet the Canadian Council of Ministers of the Environment (CCME) guidelines for pathogen control. Final C:N ratios were highest in a horse manure and bedding:SHW compost at 23:1 but ranged from 18.5 to 20.5:1 for the remaining three treatments, representing a wheat straw:SHW compost and different combinations of horse manure and bedding, SHW, and/or sheep manure. Average reduction in mass of total carbon across all the composts in the current study was 54.2%. Maturity tests at the end of the study determined that the CO2-C evolution rate in all compost products was less than 1 mg g(-1) organic matter day(-1) suggesting highly stable final compost products. Compost mass reductions all responded as exponential decay functions with R(2) values ranging from 0.84 to 0.99 regardless of compost feedstock composition. Agricultural by-products and composts are suitable feedstocks for use with SHW to generate a stable final product while meeting regulatory parameters to achieve conventional pathogen control.
authors.affiliation: PO Box 550, Department of Engineering, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia, Canada B2N 5E3. Electronic address: gprice@dal.ca.
authors.forename: G W
authors.initials: GW
authors.lastname: Price
authors.forename: Jian
authors.initials: J
authors.lastname: Zeng
authors.forename: Paul
authors.initials: P
authors.lastname: Arnold
mesh_terms: D000003:Abattoirs; D000383:Agriculture; D000818:Animals; D001673:Biodegradation, Environmental; D002244:Carbon / Q000032:analysis / Q000737:chemistry; D002417:Cattle; D004553:Electric Conductivity; D006736:Horses; D006863:Hydrogen-Ion Concentration; D008372:Manure; D009584:Nitrogen / Q000032:analysis / Q000737:chemistry; D012756:Sheep; D012987:Soil / Q000737:chemistry*
chemical_list: D008372:Manure; D012987:Soil; D002244:Carbon; D009584:Nitrogen
keywords: Compost stabilization; Horse bedding (HB); Slaughterhouse wastes (SHW); Total carbon and nitrogen; pH